Prepare for v1.0.0-rc4 (#836)

This is hopefully (🤞) the last release candidate before we cut a v1.0.0 release.

Author: jhump

internal/version.go

@@ -17,7 +17,7 @@ package internal
 //nolint:gochecknoglobals
 var (
 	// NB: These are vars instead of consts so they can be changed via -X ldflags.
-	buildVersion       = "v1.0.0-rc4-dev"
+	buildVersion       = "v1.0.0-rc4"
 	buildVersionSuffix = ""
 
 	// Version is the version to report from all binaries.